1. Field of the Invention
The present invention relates to a method and an apparatus for aligning a plurality of single-fiber cables, and also to a method of simultaneously fusion-splicing single-fiber cables.
2. Description of the Related Art
To fusion-splice a number of single-fiber cables each comprising a coated optical fiber, each pair of cables is fusion-spliced by means of a fusion-splicing apparatus designed for single-fiber cables. Specifically, those portions of the sheaths which cover the ends of the cables are removed, thus exposing the end portions of the cables, which are then cleaned. Thereafter, the end portions are cut such that each has a face such as facilitates their fusion-splicing, and the end portions are fusion-spliced to each other.
This process, i.e. removing the sheaths from the end portions of a pair of single-fiber cables, cleaning and then cutting and fusion-splicing the end portions of the fibers, usually takes 15 to 30 minutes. Since using a fusion-splicing apparatus designed for single-fiber cables, it is not possible to fusion-splice more than one pair of single-fiber cables at a time.
Accordingly, a time-saved method has been proposed to permit plural pairs of single-fiber cables to be fusion-spliced at the same time, wherein individual cables are held parallel to one another in the same plane by a holder designed specifically for holding a multi-fiber cable called a ribbon type cable, and the end portions of the cables of each pair are simultaneously fusion-spliced by means of an apparatus designed for fusion-splicing multi-fiber cables.
The aligning of the cables is performed by means of a cable-aligning apparatus having a plurality of pairs of pins arranged in two parallel rows and spaced a predetermined distance apart from each other. By setting the end portion of a cable to be fusion-spliced to another cable in the gap between an adjacent pair of pins of the first row and also in that between a corresponding pair of pins of the second row, the cables are aligned parallel to one another. The cables thus aligned are set in the groove of the holder designed for the multi-fiber cable. However, using this type of apparatus necessitates that those portions of the cables which extend from the holder be relatively long. Further, the more cables are required to be aligned, the larger the apparatus becomes. Moreover, this device has the drawback in that to set each cable in the gaps between the corresponding two pairs of pins of the first and second rows, thereby to set the cable ultimately in the groove of the fiber, is time consuming.